We are looking into a Debian repository based solution instead of Qt Online installer for Debian. We are are investigating supporting Debian packaging and repositories from Qt for delivery and installation and maintenance on Debian based Linuxes (instead or on side of Online Installer). However, host support is not in the initial scope but once the Debian module has been successfully provided, module-dev could be used for Debian host support, however not by TQC.
With the new Debian release glibc is now compatible with OpenSuse so our source binaries should work in both distros, covering the basic needs to run Qt on Debian.
Hence the effort needed by R&D is very low for OSS Debian 12, but for Debian 11 work is needed in delivery automation side.
To summarise, Patrick Franz from KDE is now doing packaging for Qt6 as Qt6 Debian maintainer so the basic dpkg packages for Debian 12 are done without TQC involvement, Also Qt6 will be part of Debian next release (Debian 11) around 2023.
Detailed plan provided in QTBUG-100385.